Damping of near-adiabatic magnetization dynamics by excitations of electron-hole pairs

Abstract

Excitation of electron hole pairs and subsequent relaxation is the most important mechanism of intrinsic damping in near-adiabatic magnetization dynamics in metallic ferromagnets. Intraband scattering dominates in the low temperature regime and is described by the breathing Fermi surface model. A Gilbert-like equation of motion is derived within this model where the constant damping scalar is replaced by a magnetization dependent and in general nonlocal damping matrix. In collinear systems the damping term shows two types of anisotropy, and in a general noncollinear situation nonlocal damping matrices enter the equation of motion. © 2010 IOP Publishing Ltd.